(^24) an environmenTal hisTory of Wildlife in england
woodland ‘specialists’, while their margins, and smaller woods, are occupied
by the more generalist species characteristic of farmland.^19
On the face of it, seventeenth-century wood-pastures might appear to have
had a closer relationship to the natural pre-Neolithic vegetation, at least as
envisaged by Vera, than coppiced woods. But in most examples small-leafed
lime was rare – it does not withstand grazing pressure well – and oak was
again the dominant tree, although elm, beech, ash and hornbeam, alone or
in various combinations, could also be found. The few wood-pastures which
survive today have usually not been managed for decades and thus lack the
regular cycles of change, from light to shade, experienced by coppices. They
thus tend to have high levels of humidity and shade, ensuring that they are
rich in lichens and bryophytes. This, while sometimes posited as an essential
difference between the two types of woodland,^20 is in reality a reflection of
recent developments. There are, however, two more important differences
between them. First, regular grazing in wood-pastures would have suppressed
the range of plants common in coppices: they were floristically poorer.
Secondly, while coppiced woods often contained ancient stools, there were
few full-grown trees of any great age, as most were felled when they reached
economic maturity at around 80–100 years, when their growth rate tended
to slow and they were large enough to be used for building houses and ships.
The pollards in wood-pastures, in contrast, continued to be cropped into old
age, and these environments thus contained a high proportion of ancient
or ‘veteran’ trees, that is, examples old for their particular species.^21 These
were, and are, important habitats, containing rotting wood, cavities, cracks
and crevices which are home to a range of rare lichens, fungi, and beetles.^22
It has been estimated that there are no less than 1,700 different species
of invertebrates in Britain which depend, directly or indirectly, on decayed
wood for some, at least, of their life cycle.^23 Snails and slugs, such as the
tree snail (Balera perversa), also flourish, feeding on both fungi, mosses and
ferns. Larger fauna, especially bats, also make their homes in ancient trees;
while birds, especially owls like the Barn Owl, nest in the numerous holes
created as the trees decay.
heaths and moors
One important difference between the landscape of the seventeenth century
and that of today was the far greater extent of heathland. Between 1800 and
1950 the area of heathland in Dorset, for example, decreased by 67%, and
large tracts had already been lost to agriculture in the course of the eighteenth
century.^24 Heaths are treeless environments formed in poor, infertile soils
overlying porous and acid sands and gravels. Many boast a characteristic
soil called a podzol, which has a grey upper level, leached of humus and iron,
overlying hard layers of ‘pan’ where these have been re-deposited. Their
vegetation features a distinctive range of dwarf shrubs, principally heather
elle
(Elle)
#1